diff --git a/src/registration.ts b/src/registration.ts
index 71e488c..23dd2e5 100644
--- a/src/registration.ts
+++ b/src/registration.ts
@@ -150,16 +150,23 @@ export const registerDidMethodNetwork = ({
   const key = `${blockchain}:${network}`;
 
   const existedFlag = DidMethodNetwork[method][key];
-  if (typeof existedFlag === 'number' && existedFlag !== networkFlag) {
-    throw new Error(
-      `DID method network '${method}' with blockchain '${blockchain}' and network '${network}' already registered with another flag '${existedFlag.toString(
-        2
-      )}'`
-    );
-  }
-
-  if (Object.values(DidMethodNetwork[method]).includes(networkFlag)) {
-    throw new Error(`DID network flag  ${DidMethodNetwork[method][key]} is already registered`);
+  if (typeof existedFlag === 'number') {
+    const isSameFlag = existedFlag === networkFlag;
+    if (!isSameFlag) {
+      throw new Error(
+        `DID method network '${method}' with blockchain '${blockchain}' and network '${network}' already registered with another flag '${existedFlag.toString(
+          2
+        )}'`
+      );
+    }
+  } else {
+    if (Object.values(DidMethodNetwork[method]).includes(networkFlag)) {
+      throw new Error(
+        `DID network flag ${networkFlag.toString(
+          2
+        )} is already registered for the another for '${method}'`
+      );
+    }
   }
   DidMethodNetwork[method][key] = networkFlag;
 };
diff --git a/tests/did.test.ts b/tests/did.test.ts
index 580dd45..ab46e5f 100644
--- a/tests/did.test.ts
+++ b/tests/did.test.ts
@@ -317,7 +317,7 @@ describe('DID tests', () => {
           method: DidMethod.Iden3,
           blockchain: Blockchain.ReadOnly,
           network: 'network',
-          networkFlag: 0b01000000 | 0b00000011,
+          networkFlag: 0b11000000 | 0b00000011,
           chainId: 104
         }
       },
@@ -436,7 +436,7 @@ describe('DID tests', () => {
         network: 'supa_net',
         networkFlag: 0b00010000 | 0b00000001
       },
-      err: 'DID network flag  undefined is already registered'
+      err: `DID network flag 10001 is already registered for the another for 'iden3'`
     }
   ];
   for (let i = 0; i < testCases.length; i++) {